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Peer reviewedOpen accessCOVID-19SARS

Infectious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Exhaled Aerosols and Efficacy of Masks During Early Mild Infection

Clinical Infectious Diseases·

Oluwasanmi O Adenaiye, Jianyu Lai, P Jacob Bueno de Mesquita, Filbert Hong, Somayeh Youssefi, Jennifer German, S H Sheldon Tai, Barbara Albert, Maria Schanz, Stuart Weston, Jun Hang, Christian Fung, Hye Kyung Chung, Kristen K Coleman, Nicolae Sapoval, Todd Treangen, Irina Maljkovic Berry, Kristin Mullins, Matthew Frieman, Tianzhou Ma, Donald K Milton

DOI
10.1093/cid/ciab797
PMID
34519774
PMCID
PMC8522431
OpenAlex
W3199915974
Study type
Journal article
Publisher
Oxford University Press (OUP)
Article type
journal-article
Integrity
current

Why this research matters now

The findings provide evidence relevant to respiratory source-control measures during early infection, including mask performance and variation in aerosol RNA shedding by viral variant. The abstract reports that the authors considered layered controls and tighter-fitting respiratory protection important in the context they studied.

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Structured evidence summary

Research question

The study examined how much SARS-CoV-2 was present in exhaled fine and coarse aerosols during early mild infection, whether the Alpha variant was associated with greater aerosol RNA shedding, and how masks affected emitted aerosol RNA.

Study design

This was a prospective clinical sampling study of COVID-19 cases, with participants providing respiratory, surface, blood, and repeated 30-minute breath samples with and without masks. Investigators measured and sequenced viral RNA, attempted viral culture, and assessed antibody responses.

Population and setting

The study enrolled 49 seronegative cases during early infection, with sampling conducted from May 2020 through April 2021. Participants had a mean of 3.8 days since symptom onset, with some providing samples at up to two visits separated by two days.

Main findings

SARS-CoV-2 RNA was detected in fine aerosols, coarse aerosols, and phone-surface samples. Masks were associated with lower aerosol RNA, with a larger reported reduction in coarse than fine aerosols, and cloth and surgical masks did not differ significantly in this analysis. Alpha-variant cases had substantially higher fine-aerosol RNA levels than cases infected with earlier viruses; two masked fine-aerosol samples were culture-positive.

Public-health relevance

The findings provide evidence relevant to respiratory source-control measures during early infection, including mask performance and variation in aerosol RNA shedding by viral variant. The abstract reports that the authors considered layered controls and tighter-fitting respiratory protection important in the context they studied.

Important limitations

The evidence comes from 49 seronegative cases sampled during a defined period, and the abstract does not establish how well the results generalize to other populations, infection stages, variants, settings, or mask-use conditions. This summary is also limited to the supplied single-article abstract and metadata; the original paper is required for decision-grade assessment of methods, analyses, and limitations.

GIDS interpretation

The article is discoverable as evidence concerning SARS-CoV-2 aerosol shedding, transmission-related study questions, variant comparisons, and mask-associated source control. It provides article-level context only and does not by itself establish or confirm a current surveillance signal.

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Related GIDS surveillance

Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.

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Evidence relationships

This article has 10 auditable classifier relationships to diseases, places, topics, and study design.

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